5.1
What is an atom?
atom the smallest particle of an element that retains the identity of the element
Is the atomic mass a whole number ? Or is the mass number a whole number? Which one is in decimals?
Atomic mass is always a whole number, mass number is in decimals (which is found below the symbol on the periodic table)
What is the difference between a period and a group in the periodic table
period a horizontal row of elements in the periodic table
group a vertical column of elements in the periodic table
During a chemical reaction, one atom can join with another atom by ____, ____, or ____ valence electrons.
Gaining, losing, or sharing
What is the arrangement for the elements on the periodic table based on?
Today's periodic table, is based on arrangement of the elements according to increasing atomic number.
What is the nucleus?
nucleus in chemistry, the positively charged centre of an atom
How do you know what the number of protons and electrons are?
By looking at the atomic number (which is found on type of the symbol on the periodic table)
List and explain the three classes of elements in the periodic table
metal typically, an element that is hard, shiny, malleable and ductile, and is a good conductor of heat and electricity
non-metal typically, an element that is not shiny, malleable, or ductile, and is a poor conductor of heat and electricity
metalloid an element that shares some properties with metals and some properties with n o n - m e t a l s
What is a valance electron
valence electron an electron in the outermost occupied energy level of an atom
What is an isotope?
isotope one of two or more forms of an element that have the same number of protons but a different number of neutrons
What is a proton, electron, and a neutron?
electron a negatively charged particle within the a t o m
proton a positively charged particle that is part of every atomic nucleus
neutron an uncharged particle that is part of almost every atomic nucleus
how do you calculate the number of neutrons ?
number of neutrons = mass number - atomic number
Why can metals be harmful to humans and animals?
Metals can be harmful if they accumulate to too high a level in the body (e.g., iron from multiple blood transfusions harming heart and liver), and exposure to toxic metals like arsenic, lead, mercury can cause organ damage through bioaccumulation and biomagnification.
Why does the reactivity of metals increase as you move down a group in the periodic table and from right to left across a period?
The farther the valence electrons are from the nucleus, the more easily they can be lost and, therefore, the more reactive the element is.
Where are the three classes of electrons on the periodic table located?
All the metals appear on the left side.
the non-metals (except hydrogen) appear on the right side.
The metalloids form a diagonal line toward the right side.
What is daltons atomic theory ?
• All matter is made up of small particles called atoms.
• Atoms cannot be created, destroyed, or divided into smaller particles.
• all atoms of the same element are identical in mass and size. The atoms of one element are different in mass and size from the atoms of other elements.
• Compounds are created when atoms of different elements link together in definite proportions.
How do you draw the Bohr Rutherford Model?
1. Draw a circle that represents the nucleus. Indicate the number of protons and neutrons in the nucleus. You can use the symbols "P*" to represent protons and "no" to represent neutrons.
2. Determine the number of electrons in the atom. Draw the different energy levels using circles around the nucleus.
3. Starting with the energy level nearest the nucleus, put in up to two electrons. Once the first energy level is full, fill the second one with up to eight electrons. Add up to eight electrons to the third energy level, and then the final two electrons to the fourth energy level.
Talk about the four main groups in the periodic table
Halogens- The halogens are the elements in Group 17. They are nonmetals which are highly reactive and extremely corrosive
Noble Gases The noble gases are the elements in Group 18. These non-metals are all odourless, colourless gases at room temperature. The main property that defines this group, however, is their non-reactivity.
Alkaline-Earth Metals The alkaline-earth metals are the elements in Group 2. These metals are highly reactive, but they are less reactive than the alkali metals.
Alkali Metals The alkali metals are the elements in Group 1 (except for hydrogen). These metals have low melting points. They are highly reactive.
How does the size of an atom change as you move down a group and across a period in the periodic table, and why?
The distance from the centre of the nucleus to the outermost electrons determines the size of an atom. As you move down a group in the periodic table, the elements have valence electrons that occupy higher and higher energy levels. The higher the level is, the farther the valence electrons are from the nucleus and the larger the atom is.
How does the energy of electrons change as their distance from the nucleus increases?
The energy of electron increases as their distance from the nucleus increases.